Threadless drill stem



Feb. 18, 1941. A. BOYNTON THREADLESS DRILL STEM Filed Sept. 22, 1938 5Sheets-Sheet 1 6o 7 .ll!

3n V 3a 3 40 Fi 4. ALEXANDER BOYNTON, INVENTOR,

A TTORNE YS.

Feb. 18, 1,941. A. BOYN'II'ON. 2,2 31;878

THREADLES S DRILL STEM Filed Sept. 22, 1958 3 Sheets-Sheet 2 ALEXANDERBOY/V ro/v,

pm VENTOR,

F'i 6 A TTORNE Y5 Feb. 18, 1941. A BQYNTON 2,231,878

'rrmmnmass DRILL sum Filed Sept. 22, 1958 s Sheets-Sheet s ALEXANDER BOYN TON,

INVENTOR,

Fi a 15. IBe ATTORNEYS.

Patented Feb. 18, 1941 2,231,878

UNITED STATES PATENT OFFICE THREADLESS DRILL STEM Alexander Boynton, SanAntonio, Tex.

Application September 22, 1938, Serial No. 231,209

8 Claims. (Cl. 285-161) My invention relates to rotary drill pipe and,second modified form of this invention with one particularly, to athreadless method and means key partially broken out.

for connecting the joints thereof together, as Fig. 10 is a longitudinalsection through the well as a method and means for connecting all twohalves of the removable connection means other pipe, shafts, and thelike. employed in Fig. 9.

The principal objects are: (l) to provide a Fig. .11 is an outside viewof the removable threadless means for connecting the joints toconnection means employed in Fig. 9 and shown gether, (2) to enable thedrill pipe tobe rotated sectionized in Fig. 10.

either clockwise or anti-clockwise without dan- Fig. 12 is a crosssection on the line |2l2, ger of the joints becoming disconnected, (3)to Fig.9.

connect the joints in such manner as to elim- Fig. 13 is a cross sectionon the line l3-l3. inate compression strains upon the male mem- Fig. 9,with one key omitted. bers and expansion strains upon the female Fig. 14.is a cross section on the line l4l4, members, (4) to minimizecrystallization. (5) to Fig. 9, .with two keys omitted. l5 eliminategalling of the mating parts, (6) to Fig. is a rolled out view of aportion of the provide greater strength than threads afford, drill pipeshowing the slots and lands of Fig. 9. (7) to prevent leakage betweenthe male and Similar characters of reference are employed female membersby employing separate replaceto refer to similar parts throughout theseveral able means for that purpose, (8) to eliminate views of eachembodiment.

2" the use of tool joints, (9) to provide for greater In Fig. 2 thelower joint of drill pipe I is speed going in and coming out of the holethan shown threadedly joined to coupling-shell 2 and can be obtained byemploying threaded connecsecured therein by poured in babbitt la, thetions, and, (10) to provide greater safety for lands lb in drill pipeand coupling-shell being employees on drilling rigs. enmeshed by andbetween the lands of the bab- By employing removable keys and keywaysbitt to prevent accidental unscrewing of the mating therewith, one-halfof the keys and matlower joint of the drill pipe. The tubular exingkeyways inclining in one direction between tension 2d and the lands lbare of such length the male and female members and the other that thebabbitt, .or other low-fusing metal or half of them inclining in theopposite direction alloy, will resist unscrewing of the drill pipe bysupplemented by replaceable automatically exa force somewhat greaterthan would be required panding packing, I attain all of the foregoing totwist the drill pipe in two between its connecobjects, as will moreclearly appear from the tions. following specification and accompanyingdraw- The upper joint of drill pipe I has a close ings in whichslidab-le fit within the coupling-shell 2 and has Fig. 1 is alongitudinal section through the its lower end engaged upon the circularshoulder removable connection means showing the parts 20. Exterior ofthe upper joint of drill pipe I of Fig. 2. assembled. the slots lo aredisposed in pairs around its Fig. 2 is a longitudinal section throughthe periphery. These slots are, preferably, parallel preferredembodiment of this invention with two above the upper end of thecoupling-shell 2 and keys partially broken away to show slots. belowthere these pairs of slots incline together,

Fig. 3 is a cross section on the line 33, Fig. as appears in Fig. 2. Allslots extend, at their 2, with one key omitted to show the slots. lowerends, into the recess 2b, partially turned Fig. 4 is a longitudinalsection through the off of the exterior of the drill pipe and partiallyI first modified form of this invention. turned out of the interior ofthe coupling-shell 1 Fig. 5 is a cross section on the line 5-5, Fig.When t e p pe end is disposed n e Shell as 4, with two keys omitted,seen in Fig. 2. The inclined portion of .slots lc Fig. 6 is a crosssection on the line 6-6. Fig. 4, in the drill p pe are adapted t0register With with two keys omitted. similarly inclined mating slots 2ain the cou- Fig. '7 is a longitudinal section through the-two p ng-Within these mating Slots, Which halves of the removable connectionmeans are cut one-half of their depth within the drill wherein the partsof Fig. 4, are partially assempipe and cut the other half of their depthwithin bled. the coupling-shell, the steel keys 3 are adapted Fig. 8 isa rolled out section of the drill pipe to be received with slightclearance. showing the slots and lands of Fig. 4. -Fig. 1 shows theassembly of the keys separate Fig, 9 is'a longitudinal-section throughthe from the comp assembly in This assembly is provided that the keysmay be placed as a unit into the position shown in Fig, 2 and that theymay be withdrawn therefrom as a unit. In practice, however, the keyassembly will be made upon the drill pipe as follows: The drive head 6,the key grip ring 5, and the key holder base 4, each having a freesliding fit over the drill pipe I, will be, in the order named, slippedover the lower end of the drill pipe (then free from coupling-shell 2)with the lower end of member 4 positioned below the upper end of slotsIc by slightly more than the length of the keys 3, members 5 and 6 beingpushed up out of the way for the time being. The keys will then beplaced in the slots Ic of the drill pipe and shoved downward in them andinto the slots 41) of the key holder base 4 (see Fig. 3) until the keyheads 3a. rest upon the annular flange 4a, the lower ends of the keysbeing still above the inclined lower portion of the slots. All keysbeing assembled within the parallel portion of the drill pipe slots Icwith the key heads resting upon the flange 4a, as stated, the grip ring5, adapted to have threaded engagement within the upper end of base 4,is then screwed down firmly upon the heads 3a. The drive head 6, whichalso is adapted to have threaded engagement within the base 4, isscrewed down until its enlarged end Ba firmly engages the upper end ofbase 4. The drill pipe is then inserted into the couplingshell 2 untilthe lower end of the drill pipe rests upon the shoulder 20. The keyassembly may then be pushed or driven downward by force applied upon thedrive head 6 until the base 4 rests upon the upper end of coupling-shell2.

The lower end of the drill pipe I has depending projections Ie, adaptedto enmesh with upstanding projections 2f of the coupling-shell, theprojections Ie being of different widths so that they will enmesh withthe projections 27 in only one position, that position being where themating slots Ic of the drill pipe and 2a of the coupling-shell areopposite each other to receive the keys 3. In Fig. 15 the drill pipeprojections IBe, similar to the projections Ie in Fig. 2, are shownirregularly spaced as above specified. The pointed ends 3b of the keyswill correct any slight imperfection in the registration of the matinghalves of the slots in the members I and 2 as the keys are entering theslots in the coupling-shell and the inclined portion of the slots in thedrill pipe. Slight clearance is provided between the adjacent sides ofprojections Ia and 21 in order to permit this, and to avoid extremeaccuracy in enmeshing said projections. As the assembled keys are forceddownward, they first travel with their outer halves uncovered in theparallel portion of the slots la, the lower deflected portion of theseslots beginning at a level even with the top of coupling-shell 2. All ofthe slots 2a in the coupling-shell are deflected to exactly match thedeflected portion of the slots la in the drill stem. In the operation offorcing the keys into the keyways, which are cut onehalf in the drillpipe and the other half in the coupling-shell, the keys bend and followthe deflected slots, as appears in Fig. 2. The cuts 30 (which may or maynot be employed) will lessen the bending force required to deflect thekeys from the parallel slots Ic into the deflected lower portion ofthese slots, and, of course, will lessen the force required to withdrawthe keys from these deflected slots.

The opening 2b, slightly wider than the keys, is turned one-half off ofthe drillpipe I and the opposite half is turned out of thecoupling-shell 2. This opening, slightly longer than the distancebetween its upper end and the top of the member 2, is a trap for brokenkeys. If any of the keys which, preferably, are made of spring steel,should eventually fatigue and break off in the keyways between the drillpipe and couplingshell, such broken keys can be driven into the recess2b from which they may be recovered when the drill pipe is withdrawnfrom the coupling-shell.

The U-cups I, which may be of leather or any other tough, yieldab-lesubstance, are adapted to be opened by pump pressure from below and willprevent any leakage of pump fluid which may attempt to escape throughthe slight clearance between the drill stem and coupling-shell.V-packing, or any other suitable substance, of course, may besubstituted for the U-cups.

It will be observed in Fig. 2 that the triangular lands Id and Id areformed between the slots in both the drill pipe I and coupling-shell 2.These lands, coacting with the deflected keys, hold the drill pipetogether and, at the same time, coact with the enmeshed projections I6and 2 to resist independent rotation of the drill pipe andcoupling-shell, thus enabling the drill pipe to be rotated in eitherdirection. While the drill pipe, coupling-shell, and keys are assembled,as in Fig. 2, every key 3 within the deflected slots in the drill pipeand coupling-shell and the enmeshed projections Ie and 2 would have tobe sheared before the drill pipe and coupling-shell could be rotated ineither direction independently of each other (see Figs. 2 and 3) When noforce is operating to pull the drill pipe and coupling-shell apart, thekeys can be forced into the deflected slots I0 and 2a by the applicationof only enough force to deflect the keys and overcome the slightresulting friction. Likewise, if no force is operating to pull the drillpipe and coupling-shell apart, the keys may be readily withdrawn byapproximately the same force as would be required to insert them. Butthe moment any force is applied to pull the drill pipe andcoupling-shell apart, the triangular lands Id and Id of the drill pipeand couplingshell will immediately impinge the keys between them, and,consequently, the keys would have to be sheared for their length beforethe drill pipe and coupling-shell could be pulled apart. Twelve keys,for example, each 3." long by A square, would require more force to soshear them than would be required to pull in two the strongest standardsizes of drill stern.

It will 'be noted that, to insert the drill stem into the well or towithdraw it therefrom, the standard practice is to set thecoupling-shell 2 down upon an elevator, which would thus place a gravityparting strain upon all joints below and thereby cause the keys to lock,while the joint or joints in the unit being added or withdrawn above theelevator rest upon the shoulder 20 and free from all parting strainbetween the drill pipe and coupling-shell. It is thus apparent that thekeys lock the joints together below the connection being made or brokenout; while the joint at such connection is free from all strain thatwould resist the insertion or withdrawal of the keys.

Reversing the operation of inserting the keys, as stated and shown forFig. 2, the same may be instantly and easily withdrawn by applying aspecial lifting tool, such as a quick-acting jack, into the angular cuts2e which cuts afford access to the under side of key holder base 4. Byraising this base the keys are withdrawn with their assembly which isforced upward over the drill pipe where it remains until the nextassembly of the drill pipe and coupling-shell is to be accomplished, ashereinbefore described.

Preferably, a connection means such as shown in Fig. 2 should beprovided for each joint of drill pipe, thus eliminating the use of tooljoints and adding greater strength to the connections, as well asallowing greater speed and less danger in making up or breaking out thedrill stem. A great percentage of all accidents on rotary drilling rigsresult from the great force frequently required to connect anddisconnect the drill stem. The slight force required to assemble theconnection shown in Fig. 2 by pressing or driving down the head 6 andthe slight force required to lift the keys by jacking up the base 4,means safety where danger has heretofore existed.

Figs. 4, 5, 6, 7 and8 illustrate the first modified form of thisinvention. The lower joint of drill stem IA may be threaded into thecouplingshell 2A and further secured to it by weld lAa. The upper jointof drill pipe IA is closely slidable within the coupling-shell 2A andhas its lower end engaged upon the internal shoulder 2A0. The U-cups 1A,which may be of leather or other tough, expansible substance, adapted tobe expanel-ed by fluid pressure from below, will prevent any leakage ofpump fluid between the drill stem and coupling-shell. Obviously,V-packing, or the like, may be employed in place of the U- cups.

Exterior of the drill pipe one-half of the inclined slots IAc aregrouped together and inclined in one direction and the other half ofsaid slots IAc' are grouped together and inclined in the oppositedirection. The inclined slots 2Aa and ZAa within the coupling-shell,Figs, 4 and 6, are likewise arranged in two groups and adapted to matewith the lower portion of the slots IAc and lAc' of the drill pipe (seeFig. 6) which shows the mating of the slots and keys. All slots in thedrill pipe and all slots in the coupling-shell are slightly wider thanthe keys 3A and each of said slots is slightly deeper than one-half ofthe thickness of the keys, which thus have a free slidable fit withinthe slots. The slots on the dril pipe are somewhat more than twice aslong as the keys in order that the keys may be assembled in units uponthe drill pipe, as will be explained later.

The keys 3A and 3A are mounted in two oppositely positioned assemblies,each assembly containing all the keys adapted to mate with the slotswhich incline in one direction and the other assembly containing all ofthe keys adapted to mate with the slots which incline in the otherdirection. Each set of keys are pre-shaped to incline in the samedirection as the slots into which they are engageable, as appears inFig. 7, wherein partial assemblies are shown for illustration, theactual assemblies being made upon the drill pipe as follows: The halfkey base 8 is placed against the drill pipe opposite the slots lAc. Thekeys 3A are then placed within the slots lAc above the base 8 andslipped downward in the slots until the key heads 3Aa land upon the halfbase 8. The half ring 9 is then placed upon the key heads 3A0. andclamped upon them by key assembling studs II which studs have threadedengagement with the half base 8. The other half base 8 is then placedupon the drill pipe opposite the slots lAc'. The keys 3A are then placedwithin the slots lAc' above the half base 8, both half bases 8 and 8having internal slots which receive the keys for one-half of theirdepth, as appears in Fig. 7. The half ring 9' is then placed upon thekey heads 3Aa and clamped upon them by studs I I, having threadedengagement with the half base 8. Each assembly of keys will remain uponthe drill pipe because the end keys of each assembly are embedded withinslots almost on opposite sides of the pipe from each other. Now, toaccomplish the connection between the drill pipe and coupling-shell, onekey assembly is pressed downward until its base rests upon the upper endof member 2A. Then the other key assembly is pressed downward until itsbase likewise rests upon the upper end of coupling-shell 2A. Theinclined surfaces 8-9, Figs. 4, 5, and 7, are for the purpose ofpermitting a comparatively close joint between the two halves of the keyassembly as the last one applied goes to place with a slight rotarymovement. The snap ring I0, having a portion cut out at Illa to enablethe ring to be compressed to a somewhat smaller diameter, is theninserted into an internal circular recess 9a, Fig. '7, of the clamp ringhalves Band 9, to hold the two halves together in which position theycannot be removed. This completes the connection between the drill pipeand coupling-shell, which cannot then be pulled apart or rotatedindependently of each other.

The lower end of the drill pipe IA has depending projections lAe, Fig.4, adapted to enmesh with upstanding projections 2A7, the projectionslAe being of difierent widths so that they will enmesh with theprojections 2A in only one position; that position being where themating slots lAc of the drill pipe and 2A1]. of the coupling-shell areopposite each other to receive the keys 3A and where the slots IAc ofthe drill pipe and 2Aa of the coupling-shell are also opposite eachother to receive the keys 3A, see Fig. 15, in which the drill pipeprojections [3e are similar. in their irregular width and spacing to theprojections lAe in Fig. 4. In Fig. 6 it will be observed that all keys3A and 3A and the enmeshed projections lAe and 2A) of the drill pipe andcoupling-shell would have to be sheared before independent rotationbetween the drill pipe'and coupling-shell could be accomplished. InFigs. 4 and 8 the two groups of slots 1A0 and lAc' within which areslidably engaged the two assemblies of keys 3A and 3A, clearly show thatthe group of keys 3A will be locked against the lands IAd and the othergroup of keys 3A will be locked against the lands lAd' if it beattempted to withdraw the drill pipe from the couplingshell. It isapparent that no such withdrawal can be accomplished without shearingall of the keys. If, for example, 12 keys, each 3" long by square stock,be employed, much more force would be required to shear the keys thanthe force which would pull the strongest drill pipe in two intermediateof the connections.

The assembly of the drill pipe and couplingshell being accomplished, asstated, if it be desired to disconnect this assembly, all that will benecessary is to remove the snap ring Ill and lift out both keyassemblies, one assembly of keys, of course, being removed first andthen the other. Each assembly of keys having their keys bent to conformto the spiral slots into which they are engaged,,it is ,apparent thateach of such key assemblies may beplaced in the position shown in Fig. 4by slight force applied above either of them and that either of them canbe removed therefrom by the application of very slight force under thekey bases 8 or 8. The angular cuts 2e give ready access for theapplication of such lifting force. As stated for the preferredembodiment of this invention, the key slots do not exert a shearingforce upon the keys until a force is applied tending to pull the pipeand coupling-shell apart. Consequently, this shearing force is alwaysabsent during the assembly or disconnection of the drill pipe andcoupling-shell, and is always present after the connection is made andthe weight of the drill pipe is carried upon the elevator under thecoupling above as per the usual practice for inserting drill pipe into awell or withdrawing it therefrom.

As stated for the preferred embodiment, if the construction shown inFig. 4 be employed, it is desirable to connect all of the drill pipejoints by that means which also avoids the use of tool joints andenables the drill stem to be rotated either clockwise or anti-clockwisewithout the danger of unscrewing or galling threads and with less dangerto the drilling screw than where threaded connections are employed.

The second modified form of this invention is illustrated in Figs. 9 to15, both inclusive. In

- Fig. 9 the lower joint of drill stem IB has threaded connection intocoupling-shell 23 to which it may be further secured by weld lBa. Withinthe coupling-shell the upper joint of drill stem 13 is closely slidableand seats upon the internal shoulder ZBb. The U-cups or packing 1B,corresponding to the similar cups 1 in Fig. 2 and IA in Fig. 4, preventleakage of the pump fluid between the drill pipe and coupling-shell, aswas stated for the preceding forms. The exterior of the drill pipe hastwo groups of parallel slots, each group being oppositely inclined, asappears in Figs. 9 and 15. The slots [B of one group are longer than theother group lBc'. Each of these slots has a depth of slightly more thanone-half the thickness of the keys 3B and 3B, each slot is slightlywider than each of said keys. Within the coupling-shell 23 there are twoother groups of oppositely inclined slots extending from the upper endof the coupling-shell. These groups of slots are of the same width anddepth as the slots in the drill pipe and mate therewith to receive thekeys 3B and 3B which keys, pre-shaped to fit the spiral form of theslots, have a close sliding fit therein. The shorter keys 3B and thelonger keys 3B are mounted in two separate assemblies (see Figs. 10 and11), both of which fit over the drill pipe; one assembly beingpositioned above the other and the upper assembly having its keys passedthrough the lower assembly. One assembly of keys has its keys inclinedin one direction and the other assembly has its keys inclined in theopposite direction, the keys of each assembly having equal length ofengagement within the mating group of slots in the coupling-shell. Bothassemblies of keys are shown in Figs. 10 and 11 for illustrativepurposes only, as the actual assemblies are made upon the drill stem, asfollows: To mount the upper assembly, the upper clamp ring l3 and theupper key base l2, in the order named, are slipped over the lower end ofthe upper drill pipe joint, the member l2 being stopped somewhat belowthe upper end of slots lBc while the member I3 is pushed further upwardout of the way. The long keys 3B are then placed in the slots lBc of thedrill pipe and pushed downward therein through the slots [211. of theupper key base I2 until the key heads 3Ba rest upon the upper key base.The upper clamp ring l3 which is adapted to have threaded engagementwithin the member [2 is then screwed down firmly upon the key heads 3Ba.The lower assembly of keys is then similarly mounted by slipping thelower clamp ring l3 and lower key base l2 over the lower end of thedrill pipe in the order named. The member I3 is shoved upward out of theWay and the short keys 3B are placed within the slots IE0 and pusheddownward in them through the slots We of the lower key base I2 untiltheir heads 3Ba' rest upon the lower key base. The lower clamp ring I3,which is adapted to have threaded engagement within the member I2, isthen screwed down firmly upon the heads 3Ba of the keys 3B completingthis assembly of the shorter keys. Both units of keys being mounted uponthe upper joint of drill pipe, as stated, the drill pipe is lowered intothe coupling-shell 23 with its lower end resting upon the internalcircular shoulder ZBb. The lower assembly of keys is then presseddownward followed by the upper assembly, the keys of which assembly passthrough slots 12a. and I3b upon the inside of the members l2 and I3,respectively, as appears in Figs. 10, 13 and 14. The angle wire 14,which, preferably, should be of spring steel, is then fitted into aconforming recess upon the periphery of both key assemblies, as appearsin Fig. 11. The ends Ma of the angle wire, which are of reducedthickness, are then secured by locking stud l5, as appears in thesection, Fig. 12, the outside view being shown in Fig. 11. The positionof all parts in the joint will then be as shown in Fig. 9.

Figs. 10 and 11 show the oppositely inclined keys 3B and 3B whichcorrespond in their deflection to the direction of the slots [B0 andIE0, respectively, in the drill pipe and their mating slots 2Ba and 2Ba,respectively of the couplingshell (see Fig. 9, also Fig. 6 for similarconstruction) Fig. 15, showing the slotted portion of the drill piperolled out, clearly shows the oppositely inclined groups of slots andhow they will be engaged by the assemblies of keys in Figs. 9 and 11.

The lower end of the drill pipe [B has depending projections lBe, Fig.9, adapted to enmesh with the upstanding projections 23 of thecoupling-shell 2B, the projections IBe being of different widths (seeFig. 15) so that they will enmesh with the projections 23 in only oneposition; that position being where the mating slots lBc of the drillpipe and 23a of the couplingshell are opposite each other to receive thelong keys 3B and where the slots IBc' of the drill pipe and 2Ba of thecoupling-shell are opposite each other to receive the short keys 3B.

It is apparent in Figs. 9, 12, 13, and 14 that all of the keys 3B and 3Band the enmeshed projections lBe and ZBf of the drill pipe andcoupling-shell would have to be sheared before independent rotation ofthe drill pipe and couplingshell could be accomplished. As stated forthe preceding embodiments, the drill stem would twist off between theconnections before this would happen. It is also apparent that the drillpipe would pull in two between the connections before the keys impingedbetween the lands [Ed and lBd' of the drill pipe and their oppositelands in the coupling-shell would be sheared by pulling upon the pipe,as was stated in connection with the two preceding embodiments.

' In order to disconnect the joint made, as in Fig. 9, proceed in thefollowing order: (1) Loosen stud I5, (2) remove angle wire [4, (3) forcethe upper assembly of keys upward out of their mating slots in the drillpipe and coupling by applying the necessary lifting force under thememberl3, the angle slots I311. being to afiord access for this purpose,(4) force the lower assembly of keys upward out of their mating slots inthe drill pipe and coupling by applying necessary lifting force underthe member l2, the angle slots 2e being to provide access for thispurpose. The drill pipe may now be lifted out of the coupling-shell,and, while so removed, the assemblies of keys will remain upon the drillpipe in readiness to be again applied, as hereinbefore stated, when itis desired to repeat the connection, as shown in Fig. 9.

If the construction shown for the second modified form of this inventionbe employed, preferably, each joint in the drill stem should be made asin Fig. 9; and if the drill stem be so connected, it will accomplish allof the purposes set out for the preceding embodiments.

Obviously, each embodiment of this invention may be employed for pipeunions and as a means for connecting shafts together. Where the wordpipe is employed in the claims herein, it is therefore intended that"shafts, rods, staffs and the like are included. Employed as a pipeunion, the enmeshed projections, such as le and 2 of Fig. 2, may beomitted and an expanding ring may be placed within the U-turn of theU-cups to make them more sensitive in preventing low pressure leaks.Packing may also be placed between the even end of the pipe and thesmooth shelf upon which the pipe engages (the enmeshing lands, such asle and 2 in Fig. 2, being omitted, as stated, in forming a union).

The means shown in the foregoing embodiment of this invention whereinkeys and keyways are-substituted for the usual threads and wherein therotary thrust, which may be in either di-. rection without danger of thejoints becoming disconnected, is borne by enmeshed projections andembedded keys, While compression and expansion strains are eliminated bythe same means which also minimize galling and crystallization, while atthe same time affording more strength and speed in operation thanthreads afford, together with the elimination of tool joints and theemployment of great force in making and breaking the connections and theemployment of replaceable U-cups or packing for the prevention of leaks,are believed to have shown and described means for accomplishing all ofthe first stated objects. Manifestly, this invention is subject to manyminor changes and substitutions in construction, which will remainwithin the scope of the stated objects and appended claims, and Ireserve the right to make such changes and substitutions.

I claim:

1. A pipe connection of the character described comprisin a pair ofnon-rotatably interfitting pipe ends, and means to hold said endsagainst axial movement comprising a plurality of keyways formedpartially on one pipe end and partially within the other pipe end, saidkeyways being inclined relative to each other, and keys disposed in saidkeyways to lock said ends against longitudinal movement due to theinclination of said keyways.

2. A pipe connection of the character described comprising a pair ofnon-rotatably interfitting pipe ends, and means to hold said endsagainst axial movement comprising a plurality of keyways formedpartially on one pipe end and partially within the other pipe end, saidkeyways being inclined relative to each other, and keys disposed in saidkeyways tolock said ends against longitudinal movement due to theinclination of said keyways, and means to hold said keys in said ways.

3. A pipe connection of the character described comprising a pair ofnon-rotatably interfitting pipe ends, and means to hold said endsagainst axial movement comprising a plurality of keyways formedpartially on one pipe end and partially within the other pipe end, saidkeyways being inclined relative to each other, and keys disposed in saidkeyways to lock said ends against longitudinal movement due to theinclination of said keyways, and means to hold said keys in said waysincluding a split head construction.

4. A drill pipe connection including a pipe section, a shell memberfixed thereto, a recess in 0 said shell member, slotted areas in saidrecess, a pipe end, slots on the periphery of said end, said slots beingaxially arranged for a part of their length and relatively inclined fora part of their length, keys to be inserted in the axial part of theslots and slipped into the inclined part of the slots, and means to locksaid keys together as a unit.

5. A drill pipe connection including a pipe section, a shell memberfixed thereon, a pipe end non-rotatably interfitting said shell,matching inclined slots on said end and in said shell, keys to fit insaid slots, and means to hold said keys together as a unit so as toresist axial thrust.

6. A drill pipe connection including a pipe section, a shell memberfixed thereon, a pipe end non-rotatably interfitting said shell,matching inclined slots on said end and in said shell, keys to fit insaid slots, and means to hold said keys together as a unit so as toresist axial thrust including a base ring.

7. A drill pipe connection including a pipe section, a shell memberfixed thereon, a pipe end non-rotatably interfitting said shell,matching inclined slots on said end and in said shell, keys to fit insaid slots, and means to hold said keystogether as a unit so as toresist axial thrust including a base ring and a hold down ring and studsto hold said rings together.

8. A drill pipe connection including a pipe section, a shell memberfixed thereon, a pipe end non-rotatably interfitting said shell,matching inclined slots on said end and in said shell, keys to fit insaid slots, and means to hold said keys together as a unit so as toresist axial thrust said keys being of different lengths.

ALEXANDER BOYNTON.

